I don't have a Conical, but buckets are great for top cropping yeast too. Clean and Sanitize your brew spoon and your empty WLP vial and screw top. Open the top of your fermenter, scoop out a healthy spoonful right off the top and carefully pour/drip it into the vial. Fill the vial about 3/4 full. Put the cap on the vial and tighten good. I should be airtight. (it's good to get a little wort in there too for yeast health) Immediately refrigerate the yeast. When ready to brew again, remove the vial, warm to room temperature and make a starter. Now you are ready for your next batch.
I usually go 3 generations deep, but I have gone to 5 with no problems. I've used vials that I've had in the fridge for over 4 months this way. Yeast are an amazingly hearty species! It's also a great way to keep a yeast library. Every WLP yeast you buy you can keep a top crop sample of that style in your fridge. It's a great way to economicaly experiment with mixing yeasts and trying different things. Just remember clean and sanitize anything that will come in contact with your Yeasties!!! Hope this helps!
